Table 1.

Comparison of morphological characters to differentiate Hymenaspleniumtholiformis, H.szechuanense, H.apogamum, and H.pseudobscurum.

Characters	H.tholiformis	H.szechuanense	H.apogamum	H.pseudobscurum
Size of lamina	13–16 × 3–5 cm	15–25 × 3–5 cm	10–20 × 3–5 cm	20–25 × 5–10 cm
Number of lateral pinnae	15–21 pairs	20–25 pairs	15–25 pairs	15–30 pairs
Pinna shape	trapeziform to trapeziform-lunate	trapeziform	quadrangular-trapeziform	trapeziform-falcate
Size of middle pinnae	2.5–3 × 0.6–1 cm	1.5–2.3 × 0.7–1 cm	2–3.5 × 0.6–1 cm	2.5–4 × 0.8–1.8 cm
Shape of pinna apex	obtuse to rounded	truncate to obtuse	obtuse to subacute	obtuse to subacute
Stipe color	shiny, black purple	shiny, dark purple	shiny, purple	not shiny or purple
Rachis color	purple	purple	purple	grayish green
Teeth	entire	retuse	entire	entire
Sori position	medial	inframedial	medial	supramedial
Indusium	single	single	single	double
Number of basalveins lacking	3–4	3–4	1–2	3–5